AUGUSTA, Maine (NEWS CENTER) -- State Toxicologist, Dr. Andrew Smith, says more than fifty percent of the homes in Maine rely on wells for their water supply, but many people do not know how safe the water they are drinking is.

"If you have never tested your well, then you don't really know how safe that water is to drink, and for some of these chemicals, such as arsenic, we have seen some very very high levels," said Smith. "If you haven't tested your well, you should test it, and the sooner you test it, the better."

Recent reports about elevated levels of naturally occurring fluoride in wells in Maine are only part of the story. Smith says high levels of arsenic, manganese, radon and even uranium have been detected in well water across the state.

He advises property owners test their well water every three to five years. He says a standard water test costs about $100. Smith says more than twenty percent of wells test positive for radon, a known carcinogen, so it is important to make sure radon is included in the screening.

"Radon is a challenge, because radon is not part of the standard water test and you have to make a specific request for that test kit," he explained.

He says some property owners who live in agricultural areas or are concerned about run-off may want to check their water more frequently.

"Depending on where you live, it may be advisable to be testing every year for bacteria or nitrates, where you are concerned potentially about a malfunctioning leach field or septic system," he stated.

If your test comes back positive for any potentially harmful substance, Dr. Smith recommends you stop drinking the water immediately while you devise a treatment plan.

"Use bottled water for just focusing on drinking and beverage preparation only, and that will be fine while you take the time to decide what your next step is," said Smith.

He says most wells can have a treatment plan put in place, but remediation can run from a few hundred to several thousand dollars. While the price may be tough to swallow, Smith says it pales in comparison with the potential health impacts prolonged consumption of contaminated well water can cause.